The present invention relates to the general technical field of agricultural machinery. The invention concerns a seeder comprising a chassis with a substantially horizontal transverse beam on which seeding elements are distributed in a regular manner, the transverse beam has a central section and two lateral sections arranged on either side of the central section in a work position and being raised substantially above the central section in a transport position, each lateral section being connected to the chassis by a respective arm and being displaceable transversely and vertically with respect to the chassis by a deformable mechanism controlled by an operating jack.
Such a seeder with a foldable chassis is displayed, for example, in the brochure “MAXIMA 2 Precision pneumatic seeders” of KUHN S. A. It comprises a chassis with a transverse beam on which seeding elements are distributed at constant and adjustable intervals. The transverse beam is constituted by a fixed central section and two lateral sections. The lateral sections are connected to the chassis via a respective arm. This mounted seeder has a working width of 6 m when the lateral sections extend on either side of the central section with an overall size for road movements of 3 m in width. For transport, the lateral sections are raised transversely and vertically above the central section for transport via a deformable mechanism controlled by an operating jack. The deformable mechanism has a connecting-rod linked to a lever by an upper articulation with an axis which is horizontal and directed in the direction of advance.
As a working width of 6 m does not permit travel on the roads, the seeder is folded to reduce the space occupied in width to a sufficient extent to permit movements on the road. In this transport position, the lateral sections are arranged one against the other above the central section. The arms and also the connecting-rods extend substantially vertically. By this end-to-end arrangement of the lateral sections in the transport position, the limits of the overall dimension for road movements in accordance with road legislation are reached. Thus, it is not possible to increase the working width of this seeder without exceeding the limits of the regulatory overall dimension for road movements.